Ref T592, remember size/position where last floating

This seems to work more reliable as the Qt mechanism,
but still suffers incorrect positions from time to time.

The floating window opens on to of the main widget,
which is uncritical but still strange why it happens

src/blackgui/dockwidget.cpp

@@ -32,6 +32,8 @@
 #include <QWidgetAction>
 #include <QWidget>
 #include <Qt>
+#include <QTimer>
+#include <QPointer>
 #include <QtGlobal>
 #include <QApplication>
 #include <QDesktopWidget>
@@ -167,13 +169,13 @@ namespace BlackGui
         QDockWidget::setWindowTitle(title);
     }
 
-    void CDockWidget::displayStatusMessage(const BlackMisc::CStatusMessage &statusMessage)
+    void CDockWidget::displayStatusMessage(const CStatusMessage &statusMessage)
     {
         if (!m_allowStatusBar || !this->isFloating()) { return; }
         m_statusBar.displayStatusMessage(statusMessage);
     }
 
-    void CDockWidget::displayStatusMessages(const BlackMisc::CStatusMessageList &statusMessages)
+    void CDockWidget::displayStatusMessages(const CStatusMessageList &statusMessages)
     {
         if (!m_allowStatusBar || !this->isFloating()) { return; }
         m_statusBar.displayStatusMessages(statusMessages);
@@ -263,14 +265,7 @@ namespace BlackGui
 
     void CDockWidget::toggleVisibility()
     {
-        if (this->isVisible())
-        {
-            this->hide();
-        }
-        else
-        {
-            this->show();
-        }
+        this->setVisible(!this->isVisible());
     }
 
     void CDockWidget::toggleFrameless()
@@ -323,7 +318,8 @@ namespace BlackGui
         const QByteArray geo(s.getGeometry());
         if (!geo.isEmpty())
         {
-            return this->restoreGeometry(geo);
+            const bool ok = this->restoreGeometry(geo);
+            if (ok) { this->rememberFloatingSizeAndPosition(); }
         }
         this->setMargins();
         return true;
@@ -346,11 +342,12 @@ namespace BlackGui
     {
         CStyleSheetUtility::useStyleSheetInDerivedWidget(this, QStyle::PE_FrameDockWidget);
         QDockWidget::paintEvent(event);
+        this->rememberFloatingSizeAndPosition();
     }
 
     void CDockWidget::mouseMoveEvent(QMouseEvent *event)
     {
-        if (!handleMouseMoveEvent(event)) { QDockWidget::mouseMoveEvent(event); } ;
+        if (!handleMouseMoveEvent(event)) { QDockWidget::mouseMoveEvent(event); }
     }
 
     void CDockWidget::keyPressEvent(QKeyEvent *event)
@@ -430,7 +427,7 @@ namespace BlackGui
         QThread::msleep(100);
 #       endif
 
-        this->setMargins();
+        this->setMargins(); // from settings or default
         if (topLevel)
         {
             if (m_windowTitleBackup != QDockWidget::windowTitle())
@@ -441,10 +438,12 @@ namespace BlackGui
             if (!m_wasAlreadyFloating)
             {
                 this->initialFloating();
+                this->rememberFloatingSizeAndPosition();
             }
             else
             {
                 if (m_wasFrameless) { this->setFrameless(true); }
+                this->restoreFloatingSizeAndPositionDeferred(); // after everything was applied move and resize
             }
             m_statusBar.show();
             m_wasAlreadyFloating = true;
@@ -584,6 +583,30 @@ namespace BlackGui
         this->setStyleSheet(qss);
     }
 
+    void CDockWidget::rememberFloatingSizeAndPosition()
+    {
+        if (!this->isFloating()) { return; }
+        m_lastFloatingSize = this->size();
+        m_lastFloatingPosition = this->pos();
+    }
+
+    void CDockWidget::restoreFloatingSizeAndPosition()
+    {
+        if (!m_lastFloatingSize.isValid() || m_lastFloatingPosition.isNull()) { return; }
+        this->resize(m_lastFloatingSize);
+        this->move(m_lastFloatingPosition);
+    }
+
+    void CDockWidget::restoreFloatingSizeAndPositionDeferred()
+    {
+        if (!m_lastFloatingSize.isValid() || m_lastFloatingPosition.isNull()) { return; }
+        QPointer<CDockWidget> myself(this);
+        QTimer::singleShot(1000, this, [ = ]
+        {
+            if (myself) { myself->restoreFloatingSizeAndPosition(); }
+        });
+    }
+
     CDockWidgetSettings CDockWidget::getSettings() const
     {
         if (this->objectName().isEmpty()) { return CDockWidgetSettings(); }

src/blackgui/dockwidget.h

@@ -236,7 +236,10 @@ namespace BlackGui
         QString m_windowTitleBackup;                  //!< original title, even if the widget title is deleted for layout purposes
         QSize m_preferredSizeWhenFloating;            //!< preferred size when floating 1st time
         QSize m_initialDockedMinimumSize;             //!< minimum size before first floating
+        QSize m_lastFloatingSize;                     //!< last floating position
         QPoint m_offsetWhenFloating;                  //!< initial offset to main window when floating first time
+        QPoint m_lastFloatingPosition;                //!< last floating position
+
         BlackMisc::CSetting<BlackGui::Settings::TDockWidget> m_settings { this, &CDockWidget::settingsChanged };
 
         //! Top level has been chaged
@@ -266,8 +269,17 @@ namespace BlackGui
         //! Force a style sheet update
         void forceStyleSheetUpdate();
 
+        //! Size and position in floating mode
+        void rememberFloatingSizeAndPosition();
+
+        //! Size and position of floating window
+        void restoreFloatingSizeAndPosition();
+
+        //! Size and position of floating window
+        void restoreFloatingSizeAndPositionDeferred();
+
         //! This widget`s settings
-        BlackGui::Settings::CDockWidgetSettings getSettings() const;
+        Settings::CDockWidgetSettings getSettings() const;
 
         //! Save settings
         void saveSettings(const BlackGui::Settings::CDockWidgetSettings &settings);